The invention relates in general to a stop-leak composition and, more particularly, the invention relates to a stop-leak composition particularly adapted for use in the cooling systems of internal combustion engines and hot water heating systems, although not necessarily limited thereto.
Stop-leak compositions found in the prior art generally consist essentially of a starchy paste such as corn starch, cereal flours and the like, mixed with a powdered metal, such as aluminum, or with powdered graphite. Some compositions also contain rosins or gums, and may include in addition a small quantity of soluble oil or soap.
Such compositions function on the theory of forming a film or coating over the leaks in, for example, internal combustion engine cooling systems. Such a film or coating is generally not of a permanent nature, so that the leak may reappear after a short time, with the result that repeated treatments of the cooling system are required. Other compositions containing a soluble oil or soap have a tendency to coat the surfaces exposed to the flow of coolant or heating fluid with an oily film, so that the stop-leak ingredients in the composition are somewhat prevented from strongly adhering to the surfaces proximate a leak, and the oily film thus formed is detrimental to proper heat transfer between the cooling system internal surfaces and the coolant fluid circulating through the cooling system.
The present invention, which is an improvement of prior U.S. Letters Patent No. 3,322,548, issued May 30, 1967, provides an improved stop-leak composition which avoids most of the shortcomings of prior art stop-leak compositions, and which further acts as an efficient rust preventer without the addition of any oil or soap to the composition, which provides a permanent seal for any hole or crack in a cooling or heating system, and which is compatible with all known types of anti-freeze compositions.
The improved stop-leak composition of the present invention presents the advantage over the stop-leak compositions disclosed and claimed in the aforesaid prior Letters Patent of providing a mixed powder which is less subject to being influenced by atmospheric humidity prior to compacting in a compacting press or pelletizing apparatus, which flows better into the compacting dies without sticking and which, after compacting in the form of dried pellets or pills, is substantially harder and thus less subject to dusting and breakage during packaging or during transportation in bulk. The improved stop-leak composition of the present invention provides better lubrication of the compacting punches and dies than the composition disclosed and claimed in the aforesaid patent, improved unmolding from the die and, in use, it has been found to dissolve more rapidly in a liquid fluid such as water and to provide an improved dispersion and suspension of the ingredients in the coolant of an internal combustion engine or in the heat transferring fluid of a heating system.